Ten-year research milestone provides valuable data for future restoration

Researcher standing on a mature reveg site at Peniup

One of Greening Australia’s flagship revegetation projects in Western Australia can now boast a second major milestone – a decade of plant research that is providing a cornucopia of valuable data to benefit future restoration.

For the past ten years, researchers from several universities and restoration experts have been visiting Greening Australia owned ‘Peniup’, a 250 hectare property in the Gondwana Link, to measure the growth and life cycle of every individual plant across 42 plots.

The large-scale restoration project was initially designed to maximise biodiversity and carbon benefits by Greening Australia’s then restoration manager, Justin Jonson, now the director of Threshold Environmental. Monitoring was built into the project from the outset.

“The research has provided a phenomenal dataset and resulted in some notable papers along the way. The work at Peniup has served as an excellent platform for looking at how plants interact and compete with one another. There is a whole dynamic that goes on between plants that this project has allowed us to see,” says Barry Heydenrych, Greening Australia conservation planner.

“For example, some eucalypts just hang in there as tiny, runty, little things even though they are 10 years old, in the shadow of much larger trees that are outcompeting them for water, nutrients and light.

In some cases, bigger shrubs have been observed providing cover for other species to germinate under, which is always good to see in an ecosystem that is hopefully going to develop and spread by itself in the long term.”

Mike Perring and Justin Jonson standing in a restored Yate woodland on Peniup on what was once bare paddock.

The plots were established on a range of different soil types to enable researchers to monitor the difference in survival rates and carbon storage potential of each plant relative to soil type.

“Some pioneer plants like certain acacias live fast and die young! They come in and they grow, perform a function of fixing nitrogen in the soil and providing nutrients, and serve as food for animals but they only live for five to seven years. Although we knew this was the case, we now have more actuate data on how long these acacia species are likely to live for.”

A paper by Justin Jonson in 2016, estimated that more than 3.8 million plants had been established on Peniup as part of the project, some of which have now reached a height of eight meters.

“Monitoring, in some cases the entire lifespan of some plants, from tiny germinant through small tree to leaf litter has been an amazing thing – it is like watching a child growing up and experiencing the milestones through its life. We have seen things come and go over the years. We normally don’t get the luxury of that.”

A key finding of some of the ongoing research at Peniup has been that biomass (weight) varies widely between plant species, soil type and species richness, directly impacting on carbon storage potential.

Some of this research provided information that was used to have the Peniup project recognised as Greening Australia’s first to generate carbon credits officially approved by the Clean Energy Regulator in December last year. In time, the generation of carbon credits will become common practice for all Greening Australia projects.

Peniup research partners for this project include Threshold Environmental, Australian National University, Murdoch University and the University of Western Australia.

The 10-year monitoring collective at Peniup, April 2018 (L-R: Dr David Freudenberger, ANU; Dr Rachel Standish, Murdoch University; Dr Mike Perring, UWA & Ghent University; Barry Heydenrych, Greening Australia; Tim Morald, UWA and Justin Jonson, Threshold Environmental & UWA).

“It is a great collaboration and we are very grateful to the numerous people and organisations who have helped achieve this significant research milestone. We look forward to many more decades of working together,” says Barry.

A further round of papers resulting from the collaboration is expected to be released next year.

The project forms part of Greening Australia’s Great Southern Landscapes Program which is working with thousands of landholders and partners to create Australia’s biggest carbon sink and establish 200,000 hectares of habitat across Southern Australia.

Key papers:

Hallet et al., 2014, ‘Seedling emergence and summer survival after direct seeding for woodland restoration at the Peniup property’.

A five year milestone paper which looked at the emergence and survival of seedlings (germinants) across different soil types. The study found that only 53% of new seedlings (germinants) survived their first summer.

Justin Jonson, 2010, ‘Ecological restoration of cleared agricultural land in Gondwana Link: lifting the bar at ‘Peniup’.

A detailed ecological restoration plan for the cleared land on the Peniup property, with information and procedures including planning, monitoring and early results.

Justin Jonson, 2016, ‘Peniup Ecological Restoration Project’.

The paper found that the project was on track to meet its objectives when evaluated against the standards of SERA (Society for Ecological Restoration Australasia). In addition, the importance of continuity of operational management, detailed planning and use of GIS were noted as is critical as lessons learned by this project.

Perring et al., 2015, ‘Soil-vegetation type, stem density and species richness influence biomass of restored woodland in south-western Australia.’

This study provided an ideal platform to investigate what may be potential drivers of spatial variation in biomass accumulation and the authors found that biomass varied widely within and among vegetation associations. Despite this, the authors found evidence of a significant association between biomass and species richness once number of individuals had been accounted for.